Automotive brake-control valve



INVENTOR BY Wn d! ATTORNEY June 16, 1925.

J. R. BARTHOLOMEW AUTOMOTIVE BRAKE CONTROL VALVE Filed April 11, 1922 TO BRAKE CHAMBER T0 SOURCE 0F FLUID PRESSURE JOHN R. BARTHOLOMEW Patented .lune 16, li925. j l y l UNITED STATES IPATENT OFFICE.

JOHN n. BARTIIOLOMEW, or BERKELEY, CALIFORNIA, AssIGNoR 'IO THE WEs'rING- OUsE AIR BRAKE COMPANY, or WILIIERDING, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

AUTOMOTIVE BRAKE-CONTROL VALVE.

Application led April 11, 1922. Serial No. 551,713.

To all 'whom t may concer/n: an exhaust valve 11 in valve chamber 12, the Be it known that I, JOHN R. BAR- valve chamber y12 being connected to an THOLOMEW, a citizen of the United States, atmospheric exhaust pipe 13. h

residing at Berkele in the county of Ala- TheI exhaust valve 11 is carried by 4an 6. meda and State of alifornia, have invented operating stem llvhaving a tubular extennew'and useful Improvements in Automosion 15 which projects out of the casing, tive Brake-Control Valves, of which the a guide piston V16 working inr the valve following is a" specification. chamber 12 being provided on the stem 14. 60 This invention relates to automotive fluid For operating the stem 14C, an operating pressure brakes, and more particularly to a rod 17 is inserted in the tubular extension brake controlling device therefor. 15, preferably vwith a coil spring 18 inter- The principal object of my invention is posed between the stem and the end ,of the to provide an improved manually operated rod. The'rod 17 is adapted' to be manually 65 brake controlling device of the above charoperated, for example, as shown in the cole Meer, l pending application of Carlton D. Stewart, ln the accompanying drawing, the single Serial N o. 551,475 filed April 11, 1922. figure is a central sectional view oi a brake ln operation, when no ressure' is applied controllin deviceI embodying my invention. to the operating rod 17, t ev stem 14 will be 70 lt has heretofore been proposed to emheld in the position shown in the drawing 20 ploy a i'luid pressure brake for controlling by the spring 19 and piston 3 is maintained the brakes on a motor vehicle and with such in the position shown, by -spring fi. 'The a brake, it is desirable to provide a controlvalve 11 is therefore unseated, establishing ling device which is promptly responsive communication from the brakec linder ipe 73 i l to slight movements to effect the application 5 to the exhaust pipe 13. If 1t is desired and release of the brakes. According to my to apply the brakes, pressure is applied to invention. the above result is accomplished the. rod 17, so that the stem 14 is first moved by the operation of application and release to cause the exhaust valve 11 to seat and valves through the movement of a push rod, cut oil the exhaust `from the brake cham- @il the brake cylinder pressure being varied acber, and then the piston 3 is moved so that cording tothe degree oit' pressure which may the stem of the supply valve 6 is actuated be applied to the push rod. to open .the valve and admit fluid under As shown in the drawing, the brake conpressure to the pipe 5 tol edect an applicatrolling device may comprise a casing `1 havtion of the brakes. ing a piston chamber 2`containing a piston The pressure of fluid vsupp-lied to the 3 subject tothe pressure of a coil spring 4. brake cylinder acts on the piston 3 and The piston chamber 2 is lconnected by pipe tends to move. the piston sov as to permit 5 to the brake cylinder or brake chamber, an the closing of the supply valve 6.

increase in pressure in which `is adapted to When the pressure of -luid sup lied to 302 i apply the brakes onfthe motor vehicle. the brake cylinder slightl exceeds t e pres- 40 A supply valve 6, contained in valve sure applied to the rod l the piston 3 will chamber and subject to the pressure of a be moved so as to allow the valve 6 to seat coil spring -8 is adapted to control comand thereby cut- Oil' the further supply oi munication through which fluid under fluid to the brake cylinder. lf the pressure pressure issu plied to the brake chamber applied to'the'rodl'? is increasedthe piston to apply the rakes, the valve chamber 7 3 will again be moved to open the valve 6 being connectedl by pipe 9 to a suitable and admit fluid to the brake cylinder until source of Huid Y'under pressure. The movethe brake cylinder pressure has been inment of iston 3 in one direction operates i creased to slightly exceed the pressure a m0 to opent e valve 6 and the exhaust oi fluid plied to the rod 17, when the piston 3 will W from piston'chamb'er 2 and brake cylinder be again operated by brake cylinder preapipe 5 is eected through/a central passage sure to permit the valve 6 to close. 10 in the piston 3, which is controlled by The brakes maybe released by relieving the pressure applied to the rod 17, when the valve 11 will be instantly lifted from its seat by the action of spring 19 to permit the exhaust of fluid from the brake chamber through pipe 5 to the exhaust pipe 13. The brakes may be fully released by allowing the valve 11 to remain open or the brakes may be partially released, that is to say the brake cylinder pressure reduced, by first relieving the pressure on the rod 17 to open the valve 11 and then applying pressure to the rod to close the valve 11.

It will now be seen from the foregoing description that the Huid pressure brakes on the motor vehicle may be quickly applied by merely applying pressure to the rod 17 and that the brake cylinder pressure Will be proportional .to the amount of pressure applied to the rod, while the brakes may be fully or gradually released by merely relieving the pressure applied to the rod 17.

It will be noted that with the above construction the operator can feel the brake application, similar to the feel of the ordinary foot brake employed on motor vehicles.

IVhile not essential to the operation, a spring 18 may be interposed between the push rod 17' and the hollow stem 15, so that when the hand depresses the rod 17, the spring 18 is compressed and the compression of the spring will determine the pressure at which the inlet valve will close.

Having now described my invention, what I claim as new and desire to secure by Let-- ters Patent, is

In an automotive fluid pressure brake, a controlling valve device comprisin a valve for contro ling the supply of fluid under pressure f r applying the brakes, an exhaust valve, a piston intermediate said valves for operating the supply valve, and a manually operated `push rod for operating said exhaust valve and piston.

In testimony whereof I have hereunto set my hand.

JOHN R. BARTHOLOMEW. 

